DPDK patches and discussions
 help / color / mirror / Atom feed
From: "Tan, Jianfeng" <jianfeng.tan@intel.com>
To: "Chen, Junjie J" <junjie.j.chen@intel.com>,
	"maxime.coquelin@redhat.com" <maxime.coquelin@redhat.com>,
	"mtetsuyah@gmail.com" <mtetsuyah@gmail.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] net/vhost: fix segfault when creating vdev dynamically
Date: Tue, 27 Mar 2018 17:42:45 +0800	[thread overview]
Message-ID: <bccc2fd8-867a-266e-7c99-8e5bbd79673e@intel.com> (raw)
In-Reply-To: <AA85A5A5E706C44BACB0BEFD5AC08BF63138CD9F@SHSMSX101.ccr.corp.intel.com>



On 3/27/2018 5:24 PM, Chen, Junjie J wrote:
>>>> On 3/28/2018 12:05 AM, Junjie Chen wrote:
>>>>> when creating vdev dynamically, vhost pmd driver start directly
>>>>> without checking TX/RX queues ready or not, and thus cause
>>>>> segmentation fault when vhost library accessing queues. This patch
>>>>> add flag to check whether queues setup or not, and add driver start
>>>>> call into dev_start to allow user start it after setting up queue.
>>>> The issue is clear now. But this patch just puts the situation before below
>> fix:
>>>> "it doesn't create the actual datagram socket until you call .dev_start()."
>>> No, if the queue exist, the datagram socket still get created in vhost_create
>> API, since the vhost_driver_register still exist in vhost_create.
>>
>> The queue can never be created, as it's still not probed.
> I think we need to separate this into two cases:
> 	Statically create vdev, the datagram recreate logical is still there since queues are exist already, this patch doesn't change anything.
> 	Dynamic create vdev, as you pointed out, queue can never be created, while this should be not valid since In normal process of creating vdev dynamically, we always need to config queues. Correct me if I'm wrong.

My point is, either vdev is created statically or dynamically, when 
probe(), queues are not setup yet definitely, then *the unix socket will 
not be created* until we set up the queues and do dev_start(). If the 
unix socket is not created, then VM cannot connect to it.

> In summary, I think the previously commit fixes the static code path and this patch fixes the dynamic code path (we need to at least setup queue once).

  reply	other threads:[~2018-03-27  9:42 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-27 16:05 Junjie Chen
2018-03-27  8:56 ` Tan, Jianfeng
2018-03-27  9:02   ` Chen, Junjie J
2018-03-27  9:10     ` Tan, Jianfeng
2018-03-27  9:24       ` Chen, Junjie J
2018-03-27  9:42         ` Tan, Jianfeng [this message]
2018-03-27 10:18           ` Chen, Junjie J
2018-03-27 13:54             ` Tan, Jianfeng
2018-03-27 11:28           ` Maxime Coquelin
2018-03-27 14:01             ` Tan, Jianfeng
2018-03-29 12:35               ` Maxime Coquelin
2018-03-29 15:35 ` [dpdk-dev] [PATCH v2] " Junjie Chen
2018-03-29 13:16   ` Maxime Coquelin
2018-03-30  6:58   ` [dpdk-dev] [PATCH v3] " Junjie Chen
2018-03-30  7:32     ` Yang, Zhiyong
2018-03-30  7:36       ` Maxime Coquelin
2018-03-30  7:35     ` Maxime Coquelin
2018-03-30  7:43     ` Maxime Coquelin
2018-04-09 12:37     ` Jens Freimann
2018-04-10  8:11       ` Chen, Junjie J

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=bccc2fd8-867a-266e-7c99-8e5bbd79673e@intel.com \
    --to=jianfeng.tan@intel.com \
    --cc=dev@dpdk.org \
    --cc=junjie.j.chen@intel.com \
    --cc=maxime.coquelin@redhat.com \
    --cc=mtetsuyah@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).